Control system apparatus for loading a value of a system parameter and preventing change thereto after a period of time

摘要

A control system for controlling an operating system stores a system parameter such as an ultimate pressure value, for an operating system. The control system allows operation of the operating system only after an initial value of the system parameter has been loaded. In one embodiment, a data generator element intended normally to specify a set point for the operating system, is used to provide the system parameter value as well. The control system provides a grace period after a value of the system parameter has been entered during which the system parameter value can be changed. After the grace period ends, the system parameter value cannot be changed by the operating system manager under normal circumstances. A light source is flashed in various patterns to indicate to personnel which of several different actions available to the control system are occurring.